Thread trimming device



Jan. 14, 1969 w. F. MAREK ET AL THREAD TRIMMING DEVI CE Sheet Filed Feb. 21, 1967 2 M p a a J W wfiwfi WWW m Jan. 14,1969

W.IF. MAREK ETAL 3,421,465

THREAD TRIMMING DEVI CE Sheet 2 0f 5 Filed Feb. 21, 1967 Jan. 14, 1969 w. F. MAREK ET AL 7 3,421,465

THREAD TRIMMING DEVICE Sheet 3 of 5 Filed Feb. 21, 1967 J 5% awe N r 4 J n/ W mMs r W; /Wfl United States Patent 8 Claims ABSTRACT OF THE DISCLOSURE The disclosure relates to an attachment for an automatic book sewer, such as a McCaine Sewer, utilizing a single thread chainstitch for sewing the side of a book. The attachment is effective automatically and continuously to trim away the upper thread and the lower loop left by the book sewing operation.

The invention relates to improvements in devices for trimming the excess connecting threads and loops from books which have been side sewn.

For purposes of economy, many books are manufactured using side sewing equipment wherein a single thread chainstitch is utilized to sew pages together along one side.

Automatic equipment, such as the McCaine Sewer, has long been known and used for this purpose. The collated printed pages of the book are fed lengthwise into the side sewing equipment. Evenly spaced holes are thereupon drilled vertically through the book, followed by stitching. Upon emerging from the sewer, a top thread connects each of the books, and along the trailing lower edge of each book a thread loop remains. These connecting threads and thread loops are undesirable.

In times past, it has been necessary to provide one or more attendants to trim these excess threads. This task is not only onerous but has increased production costs.

It is therefore an object of the invention to provide an automatic thread trimming device which eliminates the need for such attendants and which lowers manufacturing costs accordingly.

It is another object of the invention to provide a trimming machine which requires but a relatively small amount of space, and which can readily be installed either as factory equipment or on existing installations.

It is a further object of the invention to provide a trimmer which is durable and long-lived, and is reliable and flexible in operation in that it can readily be adjusted to suit a wide range of book sizes.

It is yet a further object of the invention to provide a trimmer which is relatively economical both with respect to initial cost and to upkeep, and whose operation can readily be learned even by unskilled personnel.

It is another object of the invention to provide a generally improved thread trimming device.

Other objects, together with the foregoing, are attained in the embodiment described in the following descripition and shown in the accompanying drawings in which:

FIGURE 1 is a fragmentary, enlarged, perspective view of a conventional side stitching mechanism showing a previously stitched book being urged forwardly by an upstanding spacer lug mounted on a conveyor and illustrating the excess bottom loop together with the excess upper connecting thread extending back to the book presently being stitched;

FIGURE 2 is a fragmentary front elevational view of Patented Jan. 14, 1969 the thread and loop trimming device of the invention; and,

FIGURE 3 is a fragmentary side elevational view thereof, with portions being shown in section, the planes of the view being shown by the line 33 in FIGURE 2.

While the device of the invention is susceptible of numerous physical embodiments, depending upon the environment and requirements of use, the embodiment shown and described herein has been extensively tested and used and has performed in an eminently satisfactory manner.

FIGURE 1 illustrates the book stitching station, This station forms no direct part of the present invention and is therefore not described in detail. It is shown to depict certain important parts of a piece of sewing equipment with which the device of the invention has successfully been utilized to trim away the upper thread portion 12 connecting a leading book 13 and a trailing book 14 moving through the machine in the direction of the arrow 16.

As will be appreciated, a run would ordinarily involve many hundreds or even many thousands of books, each of which undergoes the conventional stitching operation shown in FIGURE 1, followed by the thread and loop trimming operations effected by the device of the present invention and shown in FIGURES 2 and 3.

After collation of the printed pages, the books are placed lengthwise on an elongated table 17, the books being also partially supported by a longitudinal conveyor 18 provided with upstanding flights 19, or spacer lugs, or book advancing lugs, detachably and adjustably secured to the conveyor to accommodate differing book sizes.

Each book is urged forwardly by its own spacer lug, the distance or gap between the books being thereby carefully controlled. By appropriate timing mechanism, not shown, the intermittent start and stop movement of the conveyor 18 is also nicely regulated so as to afford the proper sequence with respect to drilling of the vertical holes 21 along the inner side 22 of the book, and the chainstitching of the thread 23 in the manner shown.

customarily, a bottom drill, not shown, drills upwardly through the sheets approximately one half the thickness of the book so as to form a bottom hole 26. Thereafter, a top drill 27 descends, while the conveyor has temporarily been stopped, and drills through the upper half of the book in alignment with the previously drilled lower hole 26 so as to form the throughbores 21.

At the appropriate point in the cycle, a needle 31 with a barb 32 is projected upwardly through the hole 21, the thread 23 being thereupon looped oved the barb 32 by a looper 33 comprising a looper bar 34 and a looper tube 36, or thread guide, moving or-bitally in a horizontal plane and carrying the thread with it, the thread being fed from a large bobbin, not shown.

In timed sequence the needle descends, carrying with it a loop 37, the loop 37 being carried through a previously formed lower loop 38 held in place by the conventional cast off 41 located temporarily adjacent the bottom of the book. A needle brace 42 is also customarily provided.

After the upper loop 37 is carried down through the lower loop 38 by the barb, the needle, together with the cast off and the brace, continue to descend, forming a long thread loop. The book then moves ahead relative to the needle until the next hole is reached and the needle ascends. The loop 37 at this juncture corresponds to the previously described lower loop 38 and the cycle is repeated.

Owing to the provision of a conventional stitch cutout mechanism, not shown, which is actuated When the gap occupied by the book positioning lug 19 is reached, all of the steps of the foregoing cycle are not taken. Instead, a residual loop 44 is formed on the lower trailing end of the book and must subsequently be trimmed off. So, also, the useless and undesirable upper thread portion 12, must be trimmed off between approximately the two locations indicated by the reference numerals 46 and 47.

In the trimmer of our invention, we prefer first to effect trimming of the upper thread 12, this operation being accomplished at an upper thread trimming station 50'.

As appears most clearly in FIGURE 2, a leading book 51 is connected by the upper thread 12, which extends across the gap 52, to a trailing book 53. Cutting of the upper thread 12, at the desired locations 46 and 47 is effected by a spaced pair of rapidly rotating cutting wheels 56 and 57 mounted on a spindle 58, or shaft, journaled in a horizontal bearing 59.

The nether end of the shaft 58 extends beyond the bearing and is provided with a pulley 61 driven by a belt 62 connected to an electric motor 63.

The cutting wheels 56 and 57 are capable of being selectively located axially on the shaft 53 so as to accommodate to books of various sizes.

Movement of the rapidly rotating Wheels 56 and 57 from the spaced location shown in FIGURE 2 (and in full line in FIGURE 3) into cutting engagement with the thread 12, as shown in broken line in FIGURE 3, is effected by mounting the bearing 59, as by brackets 66 on a rocker plate 67.

The rocker plate 67 is, in turn, pivotally mounted on a pin 71 carried by a spaced pair of ing from a base plate 73, secured to framework 74. The electric motor 63 is secured to the rocker plate 67 and thus moves in unison with the bearing 59 and the spindle 58 as the cutting wheels 56 and 57 move intermittently and in timed sequence toward and away from the underlying sides of the books. Customarily, the timing is so arranged that the cutters descend each time the conveyor stops to allow the holes to be drilled.

As will be appreciated, however, it is not desired to cut the upper thread at any focation other than at the points 46 and 47. Consequently, means are afforded for preventing cutting engagement between the cutting wheels 56 and 57 and the upper thread at all intermediate positons along the side of the book. In other words, cutting is to be effected only when the books have reached the position shown in FIGURE 2.

Such means comprise a spacer wheel 77 rotatably mounted on the shaft 58 at a central location between the cutting wheels 56 and 57. The spacer wheel 77, in other words, is capable of freely rotating relative to the rotating shaft 58 itself, while being restrained, however, to a selected axial location between the cutters 56 and 57, as by a suitable adjustable spacer member 78.

The diameter of the spacer wheel 77 slightly exceeds the diameters of the cutting wheels 56 and 57. Consequently, as the rocker plate 67 is periodically moved downwardly toward a book in all positions of the book except that shown in FIGURE 2, the spacer wheel 77 abuts the top side surface of the book before the cutters can engage and severthe thread.

However, when downward rocking of the cutting mechanism occurs with the books in the position shown in FIGURE 2, the periphery of the spacer wheel descends far enough into the gap to allow cutting engagement between the cutting wheels 56 and 57 and the thread at the points 46 and 47. It will be noted that as the spacer wheel 77 descends into the gap 52, the spacer wheel biases the thread 12 slightly downwardly, thus tautening the thread and rendering the operation of the cutting Wheels 56 and 57 even more effective.

arms 72 upstand- I While the trimming station 50 can be located at a position distant from the automatic sewing equipment, it has been found desirable to place it adjacent the sewer so that the elongated table support 17 and the conveyor 18 carries continuously from the sewing machine to the thread trimming device of the invention.

Thus, as appears most clearly in FIGURE 3, the stationary table 17 serves to support the outer portion of the books, and carries an outer book guide 81, whereas book movement is afforded by the central conveyor 18 and upstanding lug 19. The conveyor is moved by an appropriate structure, such as a sprocket wheel, not shown, engageable with lugs 82 mounted on the conveyor 18, which is conveniently articulated to afford an endless structure.

One side of the conveyor is supported by a track member '83; the other side, by a track member 84 secured to a narrow stationary strip 86. An inner guide 87 on the framework plate 73 serves, in conjunction with the outer guide 81, to align the books accurately.

As has been previously set forth, the thread cutting mechanism operates in a carefully timed sequence related to the cyclical operation of the sewing equipment, the cutters descending toward the subjacent conveyor each time the conveyor temporarily halts. The close physical positioning of the trimming device with respect to the sewing machine affords a further advantage in that a power take-off from the sewing machine can be utilized for timing purposes.

Thus, a shaft 91 (see FIGURE 3) can be connected to the sewing equipment so as to rotate at a velocity corresponding to the operational speed of the sewing machine.

A cam 92, including a dwell track 93 and a lobe 94, is mounted on the shaft 91 and actuates a roller-type cam follower 96, causing the associated lever 97 to oscillate between the attitudes indicated in FIGURE 3. A tension spring 101 is secured at its lower end to an eyebolt 102 mounted on the framework 74, and is attached at its upper end to a threaded, tension-adjusting member 103 afiixed to a Z-shaped bar 104 mounted on the lever 97 and biasing the adjacent end of the lever and cam roller downwardly into engagement with the cam.

A fulcrum pin 106 on a vertical framework member 107 rockably supports the oscillating lever 97, and the nether end of the lever 97 is mounted on a pin 108 pivotally connected to a hub 109 on a threaded sleeve 110. Threadably connected to the sleeve 110 is an operating rod 111, or connecting rod, threadably connected in turn to the threaded sleeve 112 of a yoke member 113. The threads on the opposite ends of the threaded stem 111 are oppositely inclined, thus providing for ready adjustment of effective rod length, similar to the arrangement in a turnbuckle.

The oscillatory motion of the timed cam 92 is transmitted from the operating rod 111 and through the yoke 113 to a pin 121 loosely journaled in the yoke 113 and secured to the bottom of the rocker plate 67. The pin 121 is vertically slidable, within limits, within the vertical track formed by the spaced, bifurcated, yoke arms 123. A compression spring 126 aligned by a keeper 127 depending from a closure cross bar 128 bears down on the pin 121, tending to urge the pin 121 and the rocker plate 67 into lowermost position. The spring 126, however, is sufiiciently resilient so that as the yoke periodically descends, carrying the rocker plate 67 with it, the spring 126 absorbs the slight shock as the cutting mechanism encounters the book.

As will be appreciated, the connecting rod 111 will previously have had its length adjusted so that its downward stroke will slightly exceed the extent of downward movement of the cutting mechanism. Provision is made, in other words, for a lost motion connection between the pin 121 and the bottom of the yoke track so that at the bottom of each stroke the pin lifts slightly from its seat; and this lifting movement is resiliently opposed by the spring 126 to absorb shock.

At the conclusion of the upper thread trimming operation, a pair of short stub thread ends 131 and 132 remain (see FIGURE 2) on the books 51 and 133, respectively. The stub ends are spaced inwardly from the respective ends 134 and 136 of the books and are readily capable of being glued or otherwise flattened out in the subsequent steps of manufacture.

Still remaining to be dealt with, however, are lower loops 143 and 144 (see FIGURE 2), as well as the loop 44 shown in FIGURE 1.

Usually, the thread loop is sufficiently rigid so that it retains a substantially horizontal attitude.

In order to deflect the loop 144 into trimming engagement with the teeth 146 of an electrically operated shearing device 147 below the table we provide an upper nozzle 151 and an associated valve 152 connected to a suitable compressed air source, not shown. The air flow, or air jet 153 is directed substantially vertically downwardly and impinges with sufficient force on the horizontal thread loop 144 so as to deflect the loop downwardly into the path of the teeth 146, cutting engagement ordinarily taking place as the book 133 advances, carrying the deflected loop 144 with it, into the teeth 146.

In order to prevent the deflected loop from prematurely returning to a substantially horizontal attitude under its own resiliency, a second, or lower nozzle 161 and valve 162 structure is preferably afforded. The air jet 163 from this member is directed at a slight upward angle, as shown in FIGURE 2, so as to impinge on the upper surface of the deflected loop and thus retain it in shearing position. Being in close proximity to the loop as cutting occurs, the jet 163 is also effective to blow the cut loop portion away from the area and thus prevents clogging of the shears and undesirable accumulations of severed loops.

Conveniently, the shears 147 located at the loop trimming station 166 are adjustably mounted in a bracket 167 secured to the framework, thus enabling the machine setup operator to locate the shearing blades 146 in a substantially horizontal attitude in close proximity to the loop to be trimmed.

While the shears can be of any suitable variety, it has been found that motor driven shears of the kind used to shear wool, for example, provide very satisfactory results.

Customarily, the shears operate continuously while the trimming machine is working. However, it is possible, by providing suitably timed switches, not shown, in the electrical conductors 173, to turn the shears on and off in synchronism with the conveyor movement and hook placement.

Comparable remarks apply to the nozzle and valve assem'blies. In other words, by suitable conventional mechanism, not shown, the valves can be synchronized with the other components of the device so that the air jets are directed against the loop only for the short intermittent periods when the loop reaches the proper trimming position.

Upon leaving the loop trimming station 166, the two loop thread remnants are approximately as short as the previously severed thread stub 132, for example, and are therefore as readily susceptible as the stubs to subsequent manufacturing operations. Objectionable thread tails are, in sum, reliably and automatically eliminated.

What is claimed is:

1. A thread trimming device for cutting a connecting upper thread and a lower thread loop formed by automatic book sewing equipment utilized in sewing the side of a book, said device comprising:

(a) a framework;

(b) a book conveyor mounted on said framework,

said conveyor being operatively connected to the book sewing equipment and being in conjunction therewith in intermittent steps along a path crossing said framework, said conveyor including flight members positioning the books to afford gaps between adjacent ones thereof;

(c) an upper thread cutting mechanism on said framework movable in timed sequence with said conveyor between a first position removed from a subjacent book and a second position in engagement therewith;

(d) a thread cutting member on said mechanism;

(e) timing means connected to said thread cutting mechanism for moving said mechanism between said first and second positions in dependence upon the intermittent movement of said conveyor, said mechanism completing a cycle of movement from said first position to said second position and back to said first position each time said conveyor halts;

and,

(f) spacer means on said upper thread cutting mechanism for spacing said cutting member from the upper thread as said spacer means encounters a book in said second position of said thread cutting mechanism, said spacer means being ineffective to space said cutting member from the upper thread when said spacer means is in registry with one of said gaps between adjacent books and said cutting mechanism is moved into said second position.

2. A thread trimming device as in claim 1 wherein said upper thread cutting mechanism further includes a rocker plate pivotally mounted on said framework, and a motor on said plate for driving said thread cutting member; and wherein said timing means includes a lever structure operatively connected to the book sewing equipment and to said rocker plate for cyclically moving said plate in dependence upon the movement of said equipment.

3. A thread trimming device as in claim 2 including a shaft journaled on said rocker plate and driven by said motor; and wherein said cutting member includes a spaced pair of cutting wheels selectively mounted on said shaft to effect severance of said upper thread at a predetermined location.

4. A thread trimming device as in claim 1 further including a lower thread loop severing mechanism mounted on said framework adjacent the path followed by the lower thread loop on a book on said conveyor.

5. A thread trimming device as in claim 4 wherein said lower thread loop severing mechanism is a powered shearing device having teeth arranged to face toward a lower thread loop moving along said loop path.

6. A thread trimming device as in claim 4 wherein said lower thread loop severing mechanism further includes pneumatic means for positioning said lower thread loop for engagement with said shearing teeth, and pneumatic means for removing the severed thread loop from the vicinity of said shearing device.

7. A thread trimming device as in claim 3 wherein said lever structure includes a lost motion connection with said rocker plate, and an interposed resilient member adjacent said connection to absorb any minor shock resulting from the engagement between said thread cutting mechanism and the book as said thread cutting mechanism moves from said first position to said second position.

8. A thread trimming device as in claim 1 wherein said spacer means includes a book engaging member located at a height below that of the lowermost portion of said thread cutting member, thereby limiting the extent of downward movement of said thread cutting member as said book engaging member abuts a subjacent book, the width of said book engaging member being less than the width of said gaps between said books, said book engaging member being rendered ineffective to space said thread cutting member away from said upper thread as said upper thread cutting mechanism moves from said first position to said second position with said book en- 2,711,703 6/1955 Duby 112-21 gaging member located in registry with one of said gaps. 3,024,746 3/1962 Hildmann 11221 3,149,595 9/1964 Ziltner 112252 References Cited UNITED STATES PATENTS 5 HERBERT F. ROSS, Primary Examiner. 1,333,594 3/1920 Allen 112-252 U.S.C1X.R.

2,496,211 1/1950 Hildmann 112252 112-21 

